Refactoring, EmblaRESTAPI->EmblaAPI + moved all speech synthesis functionality into api.dart

Author: sveinbjornt

example/pubspec.lock

@@ -139,10 +139,10 @@ packages:
     dependency: transitive
     description:
       name: http
-      sha256: "6aa2946395183537c8b880962d935877325d6a09a2867c3970c05c0fed6ac482"
+      sha256: "5895291c13fa8a3bd82e76d5627f69e0d85ca6a30dcac95c4ea19a5d555879c2"
       url: "https://pub.dev"
     source: hosted
-    version: "0.13.5"
+    version: "0.13.6"
   http_parser:
     dependency: transitive
     description:
@@ -448,10 +448,10 @@ packages:
     dependency: transitive
     description:
       name: web_socket_channel
-      sha256: ca49c0bc209c687b887f30527fb6a9d80040b072cc2990f34b9bec3e7663101b
+      sha256: d88238e5eac9a42bb43ca4e721edba3c08c6354d4a53063afaa568516217621b
       url: "https://pub.dev"
     source: hosted
-    version: "2.3.0"
+    version: "2.4.0"
   win32:
     dependency: transitive
     description:

lib/embla_core.dart

@@ -23,8 +23,7 @@ library embla_core;
 
 export 'package:embla_core/src/session.dart' show EmblaSession, EmblaSessionState;
 export 'package:embla_core/src/config.dart' show EmblaSessionConfig;
-export 'package:embla_core/src/speech.dart' show EmblaSpeechSynthesizer;
-export 'package:embla_core/src/api.dart' show EmblaRESTAPI;
+export 'package:embla_core/src/api.dart' show EmblaAPI;
 export 'package:embla_core/src/audio.dart' show AudioPlayer;
 export 'package:embla_core/src/recorder.dart' show AudioRecorder;
 export 'package:embla_core/src/common.dart' show kEmblaCoreVersion;

lib/src/api.dart

@@ -27,7 +27,7 @@ import 'package:http/http.dart' as http;
 import './common.dart';
 
 /// Send JSON POST request to API server.
-Future<Response?> _makeRequest(String apiURL, String apiKey, Map<String, dynamic> qargs,
+Future<Response?> _makePOSTRequest(String apiURL, String apiKey, Map<String, dynamic> qargs,
     [void Function(Map? result)? handler]) async {
   dlog("Sending query POST request to $apiURL: ${qargs.toString()}");
   Response? response;
@@ -68,8 +68,8 @@ Future<Response?> _makeRequest(String apiURL, String apiKey, Map<String, dynamic
   return response;
 }
 
-/// Static class wrapper for functions communicating with the Embla REST API.
-class EmblaRESTAPI {
+/// Static class wrapper for functions communicating directly with the Embla REST API.
+class EmblaAPI {
   /// Send request to clear query history for a given device ID.
   /// Boolean [allData] param determines whether all device-specific
   /// data or only query history should be deleted server-side.
@@ -83,6 +83,59 @@ class EmblaRESTAPI {
     };
 
     final String apiURL = "$serverURL$kClearHistoryEndpoint";
-    await _makeRequest(apiURL, apiKey, qargs, completionHandler);
+    await _makePOSTRequest(apiURL, apiKey, qargs, completionHandler);
+  }
+
+  /// Send request to speech synthesis API (static method).
+  ///
+  /// [text] Text to be speech synthesized
+  /// [apiKey] Server API key
+  /// Returns the resulting audio file URL or null if an error occurred.
+  static Future<String?> synthesize(String text, String? apiKey,
+      {String voiceID = kDefaultSpeechSynthesisVoice,
+      double voiceSpeed = kDefaultSpeechSynthesisSpeed,
+      String apiURL = "$kDefaultServer$kSpeechSynthesisEndpoint"}) async {
+    // Set URI
+    Uri uri;
+    try {
+      uri = Uri.parse(apiURL);
+    } on FormatException {
+      dlog("Invalid URL specified for TTS synthesis.");
+      return null;
+    }
+    // Set request headers
+    Map<String, String> headers = {
+      "X-API-Key": apiKey ?? "",
+      "Content-Type": "application/json",
+      "Accept": "application/json"
+    };
+    // Set request body
+    String body = json.encode({
+      'text': text,
+      'options': {'voice_id': voiceID, 'voice_speed': voiceSpeed.toString()}
+    });
+
+    dlog("Sending POST request to $apiURL: $body");
+    return await http.post(uri, headers: headers, body: body).timeout(kRequestTimeout).then(
+        (response) {
+      dlog("Response status: ${response.statusCode}");
+      dlog("Response body: ${response.body}");
+      if (response.statusCode != 200) {
+        dlog("Received invalid status code from TTS service.");
+        return null;
+      }
+      dynamic arg = json.decode(response.body);
+      if (arg is Map && arg.containsKey("audio_url")) {
+        // Valid response body
+        // Return the resulting audio file URL
+        return arg["audio_url"];
+      }
+      dlog("Invalid response body from TTS service.");
+      return null;
+    }, onError: (e) {
+      dlog("Error in speech synthesis: $e");
+      // Errors during request, return null
+      return null;
+    });
   }
 }

lib/src/session.dart

@@ -200,6 +200,7 @@ class EmblaSession {
       final String json = greetings.toJSON();
       dlog("Sending initial greetings message: $json");
       _channel?.sink.add(json);
+      // Immediately start streaming audio
       await _startStreaming();
     } catch (e) {
       await _error("Error connecting to server: $e");

lib/src/speech.dart

@@ -19,8 +19,8 @@ dependencies:
   logger: '^1.3.0'
   flutter_sound: '^9.2.13'
   audio_session: '^0.1.14'
-  web_socket_channel: '^2.3.0'
-  http: '^0.13.5'
+  web_socket_channel: '^2.4.0'
+  http: '^0.13.6'
   mp3_info: '^0.2.1'
 
 dev_dependencies: